/*
 * Main code for btty Babylon driver class
 *
 * Copyright (C) 1997-2000 SpellCaster Telecommunications Inc.
 * $Id: ldisc.c,v 1.3 2004/04/08 05:59:00 bcrl Exp $
 * Released under the GNU Public License. See LICENSE file for details.
 */
#include "bab_module.h"

#include <linux/module.h>

#include <linux/version.h>
#include <linux/string.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/types.h>
#include <linux/fs.h>
#include <linux/fcntl.h>
#include <linux/slab.h>
#include <linux/tty.h>
#include <linux/tty_ldisc.h>
#include <linux/errno.h>
#include <linux/signal.h>
#include <linux/interrupt.h>
#include <linux/tqueue.h>
#include <linux/proc_fs.h>
#include <linux/skbuff.h>
#include <asm/system.h>
#include <asm/param.h>

#if LINUX_VERSION_CODE > 0x020100
#include <linux/poll.h>
#endif

#include "ldisc.h"
#include "port.h"
#include "aps_if.h"
#include "msgq.h"
#include "version.h"

#define DEVCLASS_NAME	"btty"
int devclass_id;
static unsigned char port_ids[MAXPORTNUM];
static unsigned char port_ids_inuse[MAXPORTNUM];


int count ;
/*
 * Ports
 */
static port_t *register_port(void);

static port_t *port_list = NULL;
/*
 * the daemon message queue
 */
static struct MsgQ q;

/*
 * Function declarations
 */
static int l_open(struct tty_struct *tty);
static int l_ioctl (struct tty_struct *tty, struct file *filp, unsigned int cmd, unsigned long arg);
static void l_close(struct tty_struct *tty);
static void l_receive_buf(struct tty_struct *tty, const unsigned char *cp,char *fp, int count);
static int l_receive_room(struct tty_struct *tty);
static void l_write_wakeup(struct tty_struct *tty);
static void l_flush_buffer(struct tty_struct *tty);
static ssize_t l_chars_in_buffer(struct tty_struct *tty);

/* 16bit FCS Table */
__u16 fcstab[256] =
{
        0x0000, 0x1189, 0x2312, 0x329b, 0x4624, 0x57ad, 0x6536, 0x74bf,
        0x8c48, 0x9dc1, 0xaf5a, 0xbed3, 0xca6c, 0xdbe5, 0xe97e, 0xf8f7,
        0x1081, 0x0108, 0x3393, 0x221a, 0x56a5, 0x472c, 0x75b7, 0x643e,
        0x9cc9, 0x8d40, 0xbfdb, 0xae52, 0xdaed, 0xcb64, 0xf9ff, 0xe876,
        0x2102, 0x308b, 0x0210, 0x1399, 0x6726, 0x76af, 0x4434, 0x55bd,
        0xad4a, 0xbcc3, 0x8e58, 0x9fd1, 0xeb6e, 0xfae7, 0xc87c, 0xd9f5,
        0x3183, 0x200a, 0x1291, 0x0318, 0x77a7, 0x662e, 0x54b5, 0x453c,
        0xbdcb, 0xac42, 0x9ed9, 0x8f50, 0xfbef, 0xea66, 0xd8fd, 0xc974,
        0x4204, 0x538d, 0x6116, 0x709f, 0x0420, 0x15a9, 0x2732, 0x36bb,
        0xce4c, 0xdfc5, 0xed5e, 0xfcd7, 0x8868, 0x99e1, 0xab7a, 0xbaf3,
        0x5285, 0x430c, 0x7197, 0x601e, 0x14a1, 0x0528, 0x37b3, 0x263a,
        0xdecd, 0xcf44, 0xfddf, 0xec56, 0x98e9, 0x8960, 0xbbfb, 0xaa72,
        0x6306, 0x728f, 0x4014, 0x519d, 0x2522, 0x34ab, 0x0630, 0x17b9,
        0xef4e, 0xfec7, 0xcc5c, 0xddd5, 0xa96a, 0xb8e3, 0x8a78, 0x9bf1,
        0x7387, 0x620e, 0x5095, 0x411c, 0x35a3, 0x242a, 0x16b1, 0x0738,
        0xffcf, 0xee46, 0xdcdd, 0xcd54, 0xb9eb, 0xa862, 0x9af9, 0x8b70,
        0x8408, 0x9581, 0xa71a, 0xb693, 0xc22c, 0xd3a5, 0xe13e, 0xf0b7,
        0x0840, 0x19c9, 0x2b52, 0x3adb, 0x4e64, 0x5fed, 0x6d76, 0x7cff,
        0x9489, 0x8500, 0xb79b, 0xa612, 0xd2ad, 0xc324, 0xf1bf, 0xe036,
        0x18c1, 0x0948, 0x3bd3, 0x2a5a, 0x5ee5, 0x4f6c, 0x7df7, 0x6c7e,
        0xa50a, 0xb483, 0x8618, 0x9791, 0xe32e, 0xf2a7, 0xc03c, 0xd1b5,
        0x2942, 0x38cb, 0x0a50, 0x1bd9, 0x6f66, 0x7eef, 0x4c74, 0x5dfd,
        0xb58b, 0xa402, 0x9699, 0x8710, 0xf3af, 0xe226, 0xd0bd, 0xc134,
        0x39c3, 0x284a, 0x1ad1, 0x0b58, 0x7fe7, 0x6e6e, 0x5cf5, 0x4d7c,
        0xc60c, 0xd785, 0xe51e, 0xf497, 0x8028, 0x91a1, 0xa33a, 0xb2b3,
        0x4a44, 0x5bcd, 0x6956, 0x78df, 0x0c60, 0x1de9, 0x2f72, 0x3efb,
        0xd68d, 0xc704, 0xf59f, 0xe416, 0x90a9, 0x8120, 0xb3bb, 0xa232,
        0x5ac5, 0x4b4c, 0x79d7, 0x685e, 0x1ce1, 0x0d68, 0x3ff3, 0x2e7a,
        0xe70e, 0xf687, 0xc41c, 0xd595, 0xa12a, 0xb0a3, 0x8238, 0x93b1,
        0x6b46, 0x7acf, 0x4854, 0x59dd, 0x2d62, 0x3ceb, 0x0e70, 0x1ff9,
        0xf78f, 0xe606, 0xd49d, 0xc514, 0xb1ab, 0xa022, 0x92b9, 0x8330,
        0x7bc7, 0x6a4e, 0x58d5, 0x495c, 0x3de3, 0x2c6a, 0x1ef1, 0x0f78
};

/* FCS Calculation */
#define PPP_FCS(fcs, c) (((fcs) >> 8) ^ fcstab[((fcs) ^ (c)) & 0xff])


/*
 * Line dicipline struct
 */
					
static struct tty_ldisc adc_ldisc = {
	TTY_LDISC_MAGIC,	/* Magic number */
#if LINUX_VERSION_CODE >= 0x20100
	"btty",
#endif
	0,			/* Number */
	0,			/* flags */
	l_open,			/* open */
	l_close,		/* close */
	l_flush_buffer,		/* void flush_buffer */
	l_chars_in_buffer,	/* int chars_in_buffer */
	0,			/* int read(tty, file, unsigned char buf, unsigned int nr */
	0,			/* int write(...) */
	l_ioctl,		/* int ioctl */
	0,			/* void set_termios(tty, struct termios *old) */
	0,			/* int select(...) */
	l_receive_buf,
	l_receive_room,
	l_write_wakeup
};

/*
 * Debug variable 
 */

#ifdef DEBUG
static int debug=1;
#else
static int debug=0;
#endif


/*
 * Babylon wants a port connected
 */
static int b_connect(channel_t *ch, const char *phone, __u32 type)
{
	port_t *p = ch->dev;
	Req msg;

	if (debug) {
		printk("btty: b_connect\n");
	}
	if (!port_is_valid(p)) {
		printk("btty: b_connect: port (%p) not valid\n", p);
		ch->ConnectComplete(ch, 1);
		return(-1);
	}
	if (debug) printk("btty: Connected requested on %d: %p: u32: %d\n",p->channel.index,p,type);
	ch->state = CS_DIALING;
	msg.cmd=REQ_DIAL;
	msg.port=p->channel.index;
	strncpy(msg.phone_num, phone, sizeof(msg.phone_num));
	msg.pid = -1;
	queueMsg(&q,&msg,sizeof(Req));
	return(0);
}

/*
 * Babylon wants a port hungup
 */
static int b_hangup(channel_t *ch)
{
	port_t *p = ch->dev;
	Req msg;

	if (debug) {
		printk("btty: b_hangup\n");
	}
	if (!port_is_valid(p)) {
		printk("btty: b_hangup: port (%p) not valid\n", p);
		return(-1);
	}

	if (debug) printk("btty: Hangup requested on %d: %p\n",p->channel.index,p);
	ch->state = CS_DISCONNECTING;

	msg.cmd=REQ_HANGUP;
	msg.port=p->channel.index;
	msg.phone_num[0]=(char)0;
	msg.pid = -1;
	queueMsg(&q,&msg,sizeof(Req));
	return(0);
}

static int b_output(channel_t *ch, struct sk_buff *skb)
{
	port_t *p = ch->dev;
	unsigned char *buf, c;
	const unsigned char *d = skb->data;
	unsigned short fcs;
	int l = skb->len;

	if (debug>1) printk("btty: b_output(%d)\n", l);
	if (!port_is_valid(p)) {
		printk("btty: %s: port not valid\n", __FUNCTION__);
		return -EIO;
	}
	if (l > 2000)
		return -EIO;

	if (test_and_set_busy(&p->channel)) {
		printk("%s: b_output: already busy!!!\n", p->channel.device_name);
		return -EBUSY;
	}

	if (test_and_set_bit(0, &p->xbuf.lock)) {
		if (debug>1) printk("btty: b_output: busy\n");
		return -EBUSY;
	}

	p->xskb = skb;
	buf = p->xbuf.base;
	*buf++ = 0x7e;
	fcs = PPP_INITFCS;

	for (; l > 0; l--) {
		unsigned char c = *d++;
		fcs = PPP_FCS(fcs, c);
		if (0x7e == c || 0x7d == c || in_xmap(p, c)) {
			*buf++ = 0x7d;
			c ^= 0x20;
		}
		*buf++ = c;
	}

	fcs ^= 0xffff;

	c = (fcs & 0xff);
	if (0x7e == c || 0x7d == c || in_xmap(p, c)) {
		*buf++ = 0x7d;
		c ^= 0x20;
	}
	*buf++ = c;

	c = ((fcs >> 8) & 0xff);
	if (0x7e == c || 0x7d == c || in_xmap(p, c)) {
		*buf++ = 0x7d;
		c ^= 0x20;
	}
	*buf++ = c;

	*buf++ = 0x7e;
	/*memcpy(p->xbuf.head, d, l);*/
	
	p->xbuf.head = p->xbuf.base;
	p->xbuf.count = buf - p->xbuf.head;

	if (debug>1) printk("btty: b_output: writing\n");

	p->tty->flags |= (1 << TTY_DO_WRITE_WAKEUP);
	queue_task(&p->bh, &tq_immediate);
	mark_bh(IMMEDIATE_BH);
#if 0
	l_write_wakeup(p->tty);
#endif

	return 0;
}

static void b_output_bh(void *data)
{
	port_t *p = data;
	if (!port_is_valid(p)) {
		printk("btty: %s: port not valid\n", __FUNCTION__);
		return;
	}
	l_write_wakeup(p->tty);
}


/*
 * Take a port out-of-service
 */
static void unregister_port(port_t *port)
{
	unsigned long flags;
	port_t **p;
	int port_id = -1;

	if (debug) {
		printk("btty: unregister_port\n");
	}
	if(!port_is_valid(port)) {
		printk("btty: %s: port not valid\n", __FUNCTION__);
		return;
	}

	if ((CS_IDLE != port->channel.state) && (CS_UNAVAIL != port->channel.state)) {
		printk("btty: unregister_port: calling ConnectComplete(%s, %lu)\n", port->channel.device_name, port->callId);
		port->channel.state = CS_UNAVAIL;
		port->channel.ConnectComplete(&port->channel, port->callId);
	}
	/* Save out port number before trashing it */
	port_id=port->channel.index;
	
	UnregisterChannel(&port->channel);

	/* remove port from port_list */
	save_flags(flags);
	cli();
	for (p=&port_list; *p && *p!=port; p=&(*p)->next)
		;
	if (*p)
		*p = (*p)->next;
	restore_flags(flags);

	if (port->rbuf.base)
		free_page((unsigned long)port->rbuf.base);
	if (port->xbuf.base)
		free_page((unsigned long)port->xbuf.base);

	kfree(port);
	/* Set this port number as available as the last step */
	port_ids[port_id]=(char)0;
	port_ids_inuse[port_id]=(char)0;
	
	return;
}

static void btty_use(channel_t *ch)
{
	MOD_INC_USE_COUNT;
}

static void btty_unuse(channel_t *ch)
{
	MOD_DEC_USE_COUNT;
}

/*
 * Put a port in-service
 */
static port_t *register_port(void)
{
	port_t *p;
	int port_id,i;
	
	port_id = -1;
	/* Find the first free port number */
	for (i=0;i<MAXPORTNUM;i++) {
		if (port_ids[i]==(char)0) {
			port_ids[i]=(char)1;
			port_ids_inuse[i]=(char)0;
			port_id=i;
			break;
		}
	}
	if (-1 == port_id) {
		printk("btty: Could not alloocate port: Max port number (%d) exceeded",MAXPORTNUM);
		return(NULL);
	}
	p = kmalloc(sizeof(port_t), GFP_KERNEL);
	if(!p) {
		printk("btty: Couldn't allocate port\n");
		return(NULL);
	}

	memset(p, 0, sizeof(*p));
	p->magic = PORT_MAGIC;
	p->channel.index = port_id;

	sprintf(p->channel.device_name, "btty%u", p->channel.index);
	strcpy(p->channel.dev_class, "btty");

	p->channel.dev = p;
	p->channel.use = btty_use;
	p->channel.unuse = btty_unuse;
	p->channel.Output = b_output;
	p->channel.Connect = b_connect;
	p->channel.Hangup = b_hangup;
	p->channel.state = CS_UNAVAIL;
	
	p->tty = NULL;

	/* Allocate frame buffers */
	p->rbuf.base = (__u8 *) __get_free_page(GFP_KERNEL);
	p->xbuf.base = (__u8 *) __get_free_page(GFP_KERNEL);
	if(!p->rbuf.base || !p->xbuf.base)
		goto fail;

	p->rbuf.head = p->rbuf.base;
	p->rbuf.count = 0;
	p->rbuf.size = PAGE_SIZE;
	p->rbuf.fcs = PPP_INITFCS;
	p->rbuf.lock = 0;

	p->xbuf.head = p->xbuf.base;
	p->xbuf.count = 0;
	p->xbuf.size = PAGE_SIZE;
	p->xbuf.fcs = PPP_INITFCS;
	p->xbuf.lock = 0;
	p->xskb = NULL;

	p->channel.x_accm[0] = ~0L;
	p->channel.x_accm[1] = 0L;
	p->channel.x_accm[2] = 0L;
	p->channel.x_accm[3] = 0x60000000L;
	p->channel.r_accm = ~0L;

	p->bh.sync = 0;
	p->bh.routine = b_output_bh;
	p->bh.data = p;
	p->in_tx = 0;

	p->next = port_list;
	port_list = p;

	if(RegisterChannel(&p->channel)) {
		printk("btty: Channel registration failed\n");
		goto fail;
	} else {
		printk("btty: Registered port btty%d\n",p->channel.index);
	}

	return p;

fail:
	if (p->rbuf.base)
		free_page((unsigned long)p->rbuf.base);
	if (p->xbuf.base)
		free_page((unsigned long)p->xbuf.base);
	kfree(p);
	return(NULL);
}

/*
 * The port has been opened and the line discipline switched to Babylon
 * Construct, initialize and register a channel. Create and initialize
 * the control and state stucture, attach it to the tty device. 
 * Setup buffers.
 */
static int l_open(struct tty_struct *tty)
{
	port_t *p = (port_t *) tty->disc_data;

	if (debug) {
		printk("btty: l_open\n");
	}

	/* Make sure we're not already connected */
	if(p)
		return -EEXIST;
	MOD_INC_USE_COUNT;
	return 0;
}

static port_t *find_port (unsigned long num)
{
	port_t *p=port_list;
	for (p=port_list; p; p=p->next)
		if (p->channel.index == num)
			return p;
	return NULL;
}

static int l_ioctl (struct tty_struct *tty, struct file *filp, unsigned int cmd, unsigned long arg)
{
	port_t *p;
	
	/* Check we are not over our port limit */
	if (arg>MAXPORTNUM) {
		printk("btty: l_ioctrl called with bad port number (%ld)\n",arg);
		return(-EINVAL);
	}
	/* Find the port number */
	if ((p = find_port(arg))==NULL) {
		printk("btty: attach to port %lu -> not found\n", arg);
		return(-EINVAL);
	}
	/* Check it really does exist for fun */
	if (!port_is_valid(p)) {
		printk("btty: %s: port not valid\n", __FUNCTION__);
		return -EIO;
	}
	if (debug>1) {
		printk("l_ioctl: arg %ld: %p\n",arg,p);
	}
	switch (cmd) {
	case BIOC_TTY_ATTACH:
		if (debug) {
			printk("l_ioctl: tty_attach called with arg: %ld (%p)\n",arg,p);
		}
		/* Check that we are not already attached to this port */	
		if (p->tty) {
			printk("btty: attach to port %lu -> busy\n", arg);
			return(-EBUSY);
		}
		/* Crosslink the structures */
		p->tty = tty;
		tty->disc_data = p;

		/* Flush any pending buffers in the driver or line discipline */
		if(tty->ldisc.flush_buffer) {
			tty->ldisc.flush_buffer(tty);
			if (debug) printk("btty: ldisc.flush_buffer\n");
		}
		if(tty->driver.flush_buffer) {
			tty->driver.flush_buffer(tty);
			if (debug) printk("btty: driver.flush_buffer\n");
		}

		if (debug) printk("btty: attach on state %d\n",p->channel.state);
		if (CS_DIALING == p->channel.state) {   /* outgoing connection */
			if (debug) printk("btty: attach for outgoing connection\n");
			p->channel.state = CS_CONNECTED;
			p->channel.ConnectComplete(&p->channel, 0);
			p->channel.Up(&p->channel);
		} else {        /* incoming connection */
			if (debug) printk("btty: attach for incoming connection\n");
			p->channel.state = CS_CONNECTED;
			p->channel.Open(&p->channel);
			p->channel.Up(&p->channel);
		}
		return(0);
	case BIOC_TTY_SETSTATUS:
		if (debug) {
			printk("btty: l_iotcl: tty_setstatus called with arg: %ld",arg);
		}
		/* Check for a valid status */
		if ((arg<0) || (arg>CS_UNAVAIL)) {
			return(-EINVAL);
		}
		/* Set the status in babylon */
		p->channel.state = arg;
		return(0);
	case BIOC_TTY_GETSTATUS:
		if (debug>1) {
			printk("btty: l_iotcl: tty_getstatus called with arg: %ld, state %d",arg,p->channel.state);
		}
		/* Return the status in babylon */
		return(p->channel.state);
	}
	return -ENOIOCTLCMD;
}

/*
 * The port has been closed and/or the line discipline changed
 * Unregister and free the channel, buffers and the control structure
 */
static void l_close(struct tty_struct *tty)
{
	port_t *p = (port_t *) tty->disc_data;

	if (debug) {
		printk("btty: l_close\n");
	}
	if(!p) {
		return;
	}
	if (!port_is_valid(p)) {
		printk("btty: %s: port not valid\n", __FUNCTION__);
		return;
	}

	p->channel.state = CS_IDLE;
	p->channel.ConnectComplete(&p->channel, 0x100);
	p->channel.Down(&p->channel);

	tty->disc_data = NULL;
	p->tty = NULL;
	MOD_DEC_USE_COUNT;
}

/*
 * Flush the read/RX buffer for the port
 */
static void l_flush_buffer(struct tty_struct *tty) {
	port_t *p = (port_t *) tty->disc_data;

	if (debug>1) {
		printk("btty: l_flush_buffer\n");
	}

	if(!p)
		return;
	if (!port_is_valid(p)) {
		printk("btty: %s: port not valid\n", __FUNCTION__);
		return;
	}

	/* Flush the RX buffer */
	memset(p->rbuf.base, 0, p->rbuf.size);
	p->rbuf.count = 0;
	p->rbuf.head = p->rbuf.base;
}

/*
 * Return the number of characters waiting in the RX buffer
 */
static ssize_t l_chars_in_buffer(struct tty_struct *tty) {
	port_t *p = (port_t *) tty->disc_data;

	if(!p)
		return -ENODEV;
	if (!port_is_valid(p)) {
		printk("btty: %s: port not valid\n", __FUNCTION__);
		return 0;
	}
	if (debug>2) {
		printk("btty: l_chars_in_buffer(%d)\n", p->rbuf.count);
	}
	return p->rbuf.count;
}

/*
 * Validate a received frame and pass to the protocol stack
 */
int l_do_frame(port_t *p)
{
	struct sk_buff *skb;
	if (debug>1)
		printk("btty: l_do_frame\n");

	if (!port_is_valid(p)) {
		printk("btty: %s: port not valid\n", __FUNCTION__);
		return -1;
	}
	/* Check for runts */
	if(p->rbuf.count < 2)
		goto runt;

	/* Check the FCS */
	if(p->rbuf.fcs != PPP_GOODFCS)
		goto bad_crc;

	/* Chop off the FCS */
	p->rbuf.count -= 2;

	if (CS_CONNECTED != p->channel.state)
		goto drop;

	skb = dev_alloc_skb(p->rbuf.count);
	if (!skb)
		goto drop;

	if (debug>1) printk("btty: l_do_frame: copying packet\n");
	memcpy(skb_put(skb, p->rbuf.count), p->rbuf.base, p->rbuf.count);

	/* Pass the packet to Babylon */
	cli();
	ch_Input(&p->channel, skb);
	sti();

	return 0;

drop:
	if (debug) printk("btty: l_do_frame: dropping packet\n");
	return 0;

bad_crc:
	if (debug) printk("btty: Received packet with bad CRC (%04x)\n", p->rbuf.fcs);
	++p->rx_crc_errors;
	return -1;

runt:
	if (debug) printk("btty: Received runt packet\n");
	return -1;
}

/*
 * Data is available at the tty driver
 */
static void l_receive_buf(struct tty_struct *tty, const unsigned char *cp,
		char *fp, int count) {
	port_t *p = (port_t *) tty->disc_data;
	buf_t *buf = NULL;
	unsigned char c;

	if(!p)
		return;
	if (!port_is_valid(p)) {
		printk("btty: %s: port not valid\n", __FUNCTION__);
		return;
	}

	buf = &p->rbuf;

	/* Collect the characters and flags */
	while(count-- > 0) {
		p->rx_bytes++;
		c = *cp++;
		if(fp) {
			if(*fp && p->error == 0) {
				p->error = *fp;
				switch(p->error) {
					case TTY_OVERRUN:
						++p->rx_fifo_errors;
						break;
					case TTY_FRAME:
					case TTY_BREAK:
						++p->rx_frame_errors;
						break;
				}
			}
			++fp;
		}

		/* End of Frame */
		if(c == PPP_FLAG) {
			if(p->escape)
				p->error |= 0x80;

			if(buf->count && l_do_frame(p))
				p->rx_errors++;

			/* Prep the buffer for the next frame */
			buf->count = 0;
			buf->fcs = PPP_INITFCS;
			p->escape = 0;
			p->error = 0;
			continue;
		}

		/* if the packet is in error, look no further */
		if(p->error != 0)
			continue;

		/* Ignore mapped chars */
		if(in_rmap(p, c)) {
			continue;
		}

		/* Deal with escapes and escaped chars */
		if(p->escape) {
			c ^= p->escape;
			p->escape = 0;
		}
		else if(c == PPP_ESCAPE) {
			p->escape = PPP_TRANS;
			continue;
		}

		/* Store the character if there is room */
		if(buf->count < buf->size) {
			buf->base[buf->count++] = c;
			buf->fcs = PPP_FCS(buf->fcs, c);
			continue;
		}
				
		/* No room, were toast */
		if (!p->error) {
			p->rx_length_errors++;
			p->error |= 0xC0;
		}
	}
}

static int l_receive_room(struct tty_struct *tty) {
	return 65536;	/* We don't restrict incoming data */
}

/*
 * Called by the driver when it has more room. If we have more to
 * send, we do it here.
 */
static void l_write_wakeup(struct tty_struct *tty) {
	int actual;
	port_t *p =  (port_t *)tty->disc_data;

	if (debug>1) printk("btty: l_write_wakeup\n");
	/* Make sure we're connected */
	if(!p)
		return;
	if (!port_is_valid(p)) {
		printk("btty: %s: port not valid\n", __FUNCTION__);
		return;
	}
	if (test_and_set_bit(0, &p->in_tx))
		return;

	if (debug>1) printk("btty: xbuf.count: %d\n", p->xbuf.count);
	
	if(p->xbuf.count <= 0) {
		/*
		 * The serial buffer is almost empty so we should record
		 * the previous packet as sent and prep for a new buffer.
		 */
done:
		p->tx_packets++;
		tty->flags &= ~(1 << TTY_DO_WRITE_WAKEUP);
		if (p->xskb) {
			b_dev_kfree_skb(p->xskb);
			p->xskb = NULL;
			clear_busy(&p->channel);
		}
		clear_bit(0, &p->xbuf.lock);
		cli();
		clear_bit(0, &p->in_tx);
		p->channel.OutputComplete(&p->channel);
		sti();
		return;
	}

	actual = tty->driver.write(tty, 0, p->xbuf.head, p->xbuf.count);
	if (debug>1) printk("btty: actual: %d\n", actual);
	if (actual > 0) {
		p->xbuf.head += actual;
		p->xbuf.count -= actual;
		p->tx_bytes += actual;

		if (p->xbuf.count <= 0)
			goto done;
	}
	clear_bit(0, &p->in_tx);
}

/*----------------------------------------------------------------------------*/

#if LINUX_VERSION_CODE < 0x20100
static int call_read(struct inode *inode, struct file *filp, char *buf, int len)
#else
static ssize_t call_read(struct file *filp, char *buf, size_t len, loff_t *off)
#endif
{
	struct qMsg *msg;
	int ret;

	if (debug) printk("btty: call_read\n");
	if (len < 0)
		return -EINVAL;

	ret = verify_area(VERIFY_WRITE, buf, len);
	if (ret)
		return ret;

	msg = waitMsg(&q);
	if (!msg)
		return -EAGAIN;

	len = msg->len < len ? msg->len : len;
	if (copy_to_user(buf, msg->data, len))
		len = -EFAULT;
	kfree(msg);
	return len;
}

/*
 * Routine to accept data from the proc file and stuff it on the message queue
 */
#if LINUX_VERSION_CODE < 0x20100
int call_write(struct inode *i, struct file *f, const char *buf, int len)
#else
ssize_t call_write(struct file *f, const char *buf, size_t len, loff_t *off)
#endif
{
	Req msg;
	int ret;
	
	if (debug) printk("btty: call_write\n");
	/* Make sure the data size is correct */
	if (len!=sizeof(Req)) {
		printk("btty: write: data wrong size\n");
		return(-EINVAL);
	}
	if((ret = verify_area(VERIFY_READ, buf, sizeof(Req))) == 0) {
		if (copy_from_user(&msg, buf, sizeof(Req)))
			return -EFAULT;
		queueMsg(&q,&msg,sizeof(Req));
		if (debug) printk("btty: recieved req on btty%d for pid %d\n",msg.port,msg.pid);
		return(sizeof(Req));
	}
	return(-EIO);
}

/*
 * Routine to open the proc file
 */
static int call_open(struct inode *inode, struct file *filp)
{
	MOD_INC_USE_COUNT;
	if (debug) printk("btty: call_open\n");
	filp->private_data = NULL;

	return 0;
}

/*
 * Routine to release the proc file
 */
#if LINUX_VERSION_CODE < 0x20100
static void call_release(struct inode *inode, struct file *filp)
#else
static int call_release(struct inode *inode, struct file *filp)
#endif
{
	filp->private_data = NULL;
	if (debug) printk("btty: call_release\n");
	MOD_DEC_USE_COUNT;
#if LINUX_VERSION_CODE > 0x20100
	return 0;
#endif
}

/*
 * Routine to get ioctl's on the proc file.
 */
static int call_ioctl(struct inode *i, struct file *f, unsigned int cmd, unsigned long arg)
{
	port_t *p;
	int count;

	if (debug) printk("btty: call_ioctl\n");
	/* Process commands not requiring a port number */
	switch(cmd) {
	case BIOCF_TTY_RESET:
		/*
		 * Reset the driver: unregister
		 * all ports - basically return the driver to initial sane state
		 */
		for (count=0;count<MAXPORTNUM;count++) {
			/* Scan all available ports */
			if (port_ids[count]) {
				/* Get the port pointer */
				if ((p=find_port(count))!=NULL) {
					/* Kill off the port */
					unregister_port(p);
				} else {
					printk("btty: Reset of port %d failed\n",count);
				}
			}
			/* port_ids[count] = (char)0; */
		}
		return(0);
	case BIOCF_TTY_REGISTER_PORT:
		/*
		 * Function to create a new port - generally used by ttyd to
		 * create ports for dialout on startup. Function returns the port
		 * id to the userspace program as a return value to ioctl
		 */
		if ((p = register_port())!=NULL) {
			p->channel.state = CS_IDLE;
			if (debug) printk("btty: created port (%p)\n",p);
			return(p->channel.index);
		} else {
			return(-EIO);
		}
	case BIOCF_TTY_FIND_PORT:
		/* Find the first free port number */
		count = -1;
		for (count=0;count<MAXPORTNUM;count++) {
			/* if the port is a registered port */
			if ((port_ids[count]==(char)1)  && (port_ids_inuse[count]==(char)0)) {
				if (debug) printk("btty: call_ioctl: found port %d\n",count);
			    /* port_ids[count]=(char)1; */
			    port_ids_inuse[count]=(char)1;
				return(count);
			}
		}

		if (debug) printk("btty: call_ioctl: find port: maximum ports reached\n");
		return(-EIO);
	case BIOCF_TTY_KILL:
		return(0);
	case BIOCF_TTY_REUSE_PORT:
		
		/* Mark port as avaialable for use */
		count = (int) arg;
		port_ids_inuse[count] = (char)0;
		if (debug) printk("btty: call_ioctl: port %d marked as available\n",count);


		return(0);
	}
	/*
	 * Process the remaining commands that require a port number with lots
	 * of checks for programmers that are morons
	 */
	if ((arg<0) || (arg>MAXPORTNUM)) {
		if (debug) printk("btty: passed invalid port num (%ld)\n", arg);
		return(-EINVAL);
	}
	/* Convert the port number to a port pointer*/
	if ((p=find_port(arg))==NULL) {
		return(-EINVAL);
	}
	/* Double check this is valid in case the programmer is a moron */
	if (!port_is_valid(p)) {
		printk("btty: passed invalid port (%p)\n", p);
		return -EIO;
	}
	if (debug) {
		printk("btty: call_iotcl: called with cmd: %d and arg: %ld (%p)\n",cmd,arg,p);
	}
	/* Process the command */
	switch (cmd) {
	case BIOCF_TTY_STAT_IDLE:
		p->channel.state = CS_IDLE;
		return(0);
	case BIOCF_TTY_STAT_DIALING:
		p->channel.state = CS_DIALING;
		return(0);
	case BIOCF_TTY_STAT_RINGING:
		p->channel.state = CS_RINGING;
		return(0);
	case BIOCF_TTY_STAT_CONNECTING:
		p->channel.state = CS_CONNECTING;
		return(0);
	case BIOCF_TTY_STAT_CONNECTED:
		p->channel.state = CS_CONNECTED;
		return(0);
	case BIOCF_TTY_STAT_DISCONNECTING:
		p->channel.state = CS_DISCONNECTING;
		return(0);
	case BIOCF_TTY_STAT_STALLED:
		p->channel.state = CS_STALLED;
		return(0);
	case BIOCF_TTY_STAT_UNAVAIL:
		p->channel.state = CS_UNAVAIL;
		return(0);
	case BIOCF_TTY_CONN_FAILED:
		/*
		 * Special function to set the status to idle and pass along
		 * that we are failed the connection
		 */
		p->channel.state = CS_IDLE;
		p->channel.ConnectComplete(&p->channel, -2);
		return(0);
	case BIOCF_TTY_UNREGISTER_PORT:
		unregister_port(p);
		return(0);
	}
	return(-ENOIOCTLCMD);

}

/*
 * Routine to see if there is any data waiting for the proc file
 */
#if LINUX_VERSION_CODE < 0x20100
static int call_select(struct inode *inode, struct file *filp, int sel_type, select_table *wait)
{
	int ret;
	if (debug) printk("btty: call_select\n");
	switch (sel_type) {
	case SEL_IN:	/* read */
		select_wait(&q.wait, wait);
		ret = !!q.msgQ;
		break;
	case SEL_OUT:	/* write */
		ret = 1;
		break;
	default:
		ret = 0;
		break;
	}
	return ret;
}
#else
static unsigned call_poll(struct file *filp, poll_table *wait)
{
	int ret;

	poll_wait(filp, &q.wait, wait);

	ret = POLLOUT | POLLWRNORM;
	if (!!q.msgQ)
		ret |= POLLIN | POLLRDNORM;
	return ret;
}
#endif

static struct file_operations call_file_operations = {
	.read		= call_read,
	.write		= call_write,
#if LINUX_VERSION_CODE < 0x20100
	.select		= call_select,	/* select */
#else
	.poll		= call_poll,
#endif
	.ioctl		= call_ioctl,	/* ioctl */
	.open		= call_open,
	.release	= call_release,
};

static struct inode_operations call_inode_operations = {
	&call_file_operations,
	0,
};

static struct proc_dir_entry proc_ttyctrl = {
	0, 8, "bttyctrl", S_IFREG | S_IWUSR | S_IRUSR | S_IRGRP | S_IROTH, 1, 0, 0, 
	0, &call_inode_operations, 0,
	0, 0, 0, 0
};


/*----------------------------------------------------------------------------*/
/*
 * This device class is alive!
 */
int init_module()
{
	pr_info("SpellCaster Babylon TTY Device Class v%s Loaded\n", version);
	pr_info("Copyright (C) 1996 - 2000 SpellCaster Telecommunications Inc.\n");

	initMsgQ(&q);

	devclass_id = RegisterDeviceClass(DEVCLASS_NAME);
	if(devclass_id < 0) {
		pr_info("btty: TTY Device class already registered!\n");
		return -1;
	}

	if (tty_register_ldisc(N_BAB, &adc_ldisc)) {
		printk(KERN_INFO "btty: tty_register_ldisc failed\n");
		goto fail_notty;
	}

	if (proc_register(&proc_root, &proc_ttyctrl)) {
		printk(KERN_INFO "btty: proc_register failed\n");
		goto fail_noproc;
	}

	memset(&port_ids,(char)0,MAXPORTNUM);
	memset(&port_ids_inuse,(char)0,MAXPORTNUM);
	return 0;

/*fail:
	proc_unregister(&proc_root, proc_ttyctrl.low_ino);
 */
fail_noproc:
	tty_register_ldisc(N_BAB, NULL);
fail_notty:
	UnregisterDeviceClass(devclass_id);
	return -1;
}

/*
 * This device class is toast
 */
void cleanup_module()
{
	cli();
	while (port_list) {
		unregister_port(port_list);
	}
	sti();

	proc_unregister(&proc_root, proc_ttyctrl.low_ino);
	tty_register_ldisc(N_BAB, NULL);
	UnregisterDeviceClass(devclass_id);
	if (debug) printk("btty: Cleanup done\n");
}